Fix poll bugs.

app/src/main/java/org/thoughtcrime/securesms/database/MessageTable.kt

@@ -2228,6 +2228,7 @@ open class MessageTable(context: Context?, databaseHelper: SignalDatabase) : Dat
       reactions.deleteReactions(MessageId(messageId))
       deleteGroupStoryReplies(messageId)
       disassociateStoryQuotes(messageId)
+      polls.deletePoll(messageId)
       disassociatePollFromPollTerminate(polls.getPollTerminateMessageId(messageId))
 
       val threadId = getThreadIdForMessage(messageId)

app/src/main/java/org/thoughtcrime/securesms/database/PollTables.kt

@@ -700,6 +700,13 @@ class PollTables(context: Context?, databaseHelper: SignalDatabase?) : DatabaseT
       .readToSingleBoolean()
   }
 
+  fun deletePoll(messageId: Long) {
+    writableDatabase
+      .delete(PollTable.TABLE_NAME)
+      .where("${PollTable.MESSAGE_ID} = ?", messageId)
+      .run()
+  }
+
   private fun isPending(pollId: Long, optionId: Long, voterId: Long): Boolean {
     return readableDatabase
       .exists(PollVoteTable.TABLE_NAME)